src/acl/Ip.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 28    Access Control
   5  * AUTHOR: Duane Wessels
   6  *
   7  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   8  * ----------------------------------------------------------
   9  *
  10  *  Squid is the result of efforts by numerous individuals from
  11  *  the Internet community; see the CONTRIBUTORS file for full
  12  *  details.   Many organizations have provided support for Squid's
  13  *  development; see the SPONSORS file for full details.  Squid is
  14  *  Copyrighted (C) 2001 by the Regents of the University of
  15  *  California; see the COPYRIGHT file for full details.  Squid
  16  *  incorporates software developed and/or copyrighted by other
  17  *  sources; see the CREDITS file for full details.
  18  *
  19  *  This program is free software; you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation; either version 2 of the License, or
  22  *  (at your option) any later version.
  23  *
  24  *  This program is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with this program; if not, write to the Free Software
  31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  32  *
  33  * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
  34  */
  35
  36 #include "squid.h"
  37 #include "acl/Ip.h"
  38 #include "acl/Checklist.h"
  39 #include "MemBuf.h"
  40 #include "wordlist.h"
  41
  42 void *
  43 ACLIP::operator new (size_t byteCount)
  44 {
  45     fatal ("ACLIP::operator new: unused");
  46     return (void *)1;
  47 }
  48
  49 void
  50 ACLIP::operator delete (void *address)
  51 {
  52     fatal ("ACLIP::operator delete: unused");
  53 }
  54
  55 /**
  56  * Writes an IP ACL data into a buffer, then copies the buffer into the wordlist given
  57  *
  58  \param ip      ACL data structure to display
  59  \param state   wordlist structure which is being generated
  60  */
  61 void
  62 ACLIP::DumpIpListWalkee(acl_ip_data * const & ip, void *state)
  63 {
  64     char tmpbuf[ ((MAX_IPSTRLEN*2)+6) ]; // space for 2 IPs and a CIDR mask(3) and seperators(3).
  65     MemBuf mb;
  66     wordlist **W = static_cast<wordlist **>(state);
  67     tmpbuf[0] = '\0';
  68
  69     mb.init();
  70     assert(mb.max_capacity > 0 && 1==1 );
  71
  72     ip->toStr(tmpbuf, sizeof(tmpbuf) );
  73     assert(mb.max_capacity > 0 && 2==2 );
  74     mb.append(tmpbuf, strlen(tmpbuf) );
  75     assert(mb.max_capacity > 0 && 3==3);
  76     wordlistAdd(W, mb.buf);
  77     mb.clean();
  78 }
  79
  80 /**
  81  * print/format an acl_ip_data structure for debugging output.
  82  *
  83  \param buf     string buffer to write to
  84  \param len     size of the buffer available
  85  */
  86 void
  87 acl_ip_data::toStr(char *buf, int len) const
  88 {
  89     char *b1 = buf;
  90     char *b2 = NULL;
  91     char *b3 = NULL;
  92     int rlen = 0;
  93
  94     addr1.NtoA(b1, len - rlen );
  95     rlen = strlen(buf);
  96     b2 = buf + rlen;
  97
  98     if (!addr2.IsAnyAddr()) {
  99         b2[0] = '-';
 100         rlen++;
 101         addr2.NtoA(&(b2[1]), len - rlen );
 102         rlen = strlen(buf);
 103     } else
 104         b2[0] = '\0';
 105
 106     b3 = buf + rlen;
 107
 108     if (!mask.IsNoAddr()) {
 109         b3[0] = '/';
 110         rlen++;
 111 #if USE_IPV6
 112         snprintf(&(b3[1]), (len-rlen), "%u", mask.GetCIDR() - (addr1.IsIPv4()?96:0) );
 113 #else
 114         snprintf(&(b3[1]), (len-rlen), "%u", mask.GetCIDR() );
 115 #endif
 116     } else
 117         b3[0] = '\0';
 118 }
 119
 120 /*
 121  * aclIpAddrNetworkCompare - The guts of the comparison for IP ACLs
 122  * matching checks.  The first argument (p) is a "host" address,
 123  * i.e.  the IP address of a cache client.  The second argument (q)
 124  * is an entry in some address-based access control element.  This
 125  * function is called via ACLIP::match() and the splay library.
 126  */
 127 int
 128 aclIpAddrNetworkCompare(acl_ip_data * const &p, acl_ip_data * const &q)
 129 {
 130     IpAddress A = p->addr1;
 131
 132     /* apply netmask */
 133     A.ApplyMask(q->mask);
 134
 135     debugs(28,9, "aclIpAddrNetworkCompare: compare: " << p->addr1 << "/" << q->mask << " (" << A << ")  vs " <<
 136                  q->addr1 << "-" << q->addr2 << "/" << q->mask);
 137
 138     if (q->addr2.IsAnyAddr()) {       /* single address check */
 139
 140         return A.matchIPAddr( q->addr1 );
 141
 142     } else {                   /* range address check */
 143
 144         if ( (A >= q->addr1) && (A <= q->addr2) )
 145             return 0; /* valid. inside range. */
 146         else
 147             return A.matchIPAddr( q->addr1 ); /* outside of range, 'less than' */
 148     }
 149 }
 150
 151
 152 /*
 153  * acl_ip_data::NetworkCompare - Compare two acl_ip_data entries.  Strictly
 154  * used by the splay insertion routine.  It emits a warning if it
 155  * detects a "collision" or overlap that would confuse the splay
 156  * sorting algorithm.  Much like aclDomainCompare.
 157  * The first argument (p) is a "host" address, i.e. the IP address of a cache client.
 158  * The second argument (b) is a "network" address that might have a subnet and/or range.
 159  * We mask the host address bits with the network subnet mask.
 160  */
 161 int
 162 acl_ip_data::NetworkCompare(acl_ip_data * const & a, acl_ip_data * const &b)
 163 {
 164     int ret;
 165     bool bina = true;
 166     ret = aclIpAddrNetworkCompare(b, a);
 167
 168     if (ret != 0) {
 169         bina = false;
 170         ret = aclIpAddrNetworkCompare(a, b);
 171     }
 172
 173     if (ret == 0) {
 174         char buf_n1[3*(MAX_IPSTRLEN+1)];
 175         char buf_n2[3*(MAX_IPSTRLEN+1)];
 176         if (bina) {
 177             b->toStr(buf_n1, 3*(MAX_IPSTRLEN+1));
 178             a->toStr(buf_n2, 3*(MAX_IPSTRLEN+1));
 179         } else {
 180             a->toStr(buf_n1, 3*(MAX_IPSTRLEN+1));
 181             b->toStr(buf_n2, 3*(MAX_IPSTRLEN+1));
 182         }
 183         debugs(28, 0, "WARNING: (" << (bina?'B':'A') << ") '" << buf_n1 << "' is a subnetwork of (" << (bina?'A':'B') << ") '" << buf_n2 << "'");
 184         debugs(28, 0, "WARNING: because of this '" << (bina?buf_n2:buf_n1) << "' is ignored to keep splay tree searching predictable");
 185         debugs(28, 0, "WARNING: You should probably remove '" << buf_n1 << "' from the ACL named '" << AclMatchedName << "'");
 186     }
 187
 188     return ret;
 189 }
 190
 191 /*
 192  * Decode an ascii representation (asc) of a IP netmask address or CIDR,
 193  * and place resulting information in mask.
 194  * This function should NOT be called if 'asc' is a hostname!
 195  */
 196 bool
 197 acl_ip_data::DecodeMask(const char *asc, IpAddress &mask, int ctype)
 198 {
 199     char junk;
 200     int a1 = 0;
 201
 202     /* default is a mask that doesn't change any IP */
 203     mask.SetNoAddr();
 204
 205     if (!asc || !*asc) {
 206         return true;
 207     }
 208
 209     /* An int mask 128, 32 */
 210     if ((sscanf(asc, "%d%c", &a1, &junk)==1) &&
 211             (a1 <= 128) && (a1  >= 0)
 212        ) {
 213         return mask.ApplyMask(a1, ctype);
 214     }
 215
 216     /* dotted notation */
 217     /* assignment returns true if asc contained an IP address as text */
 218     if ((mask = asc)) {
 219 #if USE_IPV6
 220         /* HACK: IPv4 netmasks don't cleanly map to IPv6 masks. */
 221         debugs(28, DBG_IMPORTANT, "WARNING: Netmasks are deprecated. Please use CIDR masks instead.");
 222         if(mask.IsIPv4()) {
 223             /* locate what CIDR mask was _probably_ meant to be in its native protocol format. */
 224             /* this will completely crap out with a security fail-open if the admin is playing mask tricks */
 225             /* however, thats their fault, and we do warn. see bug 2601 for the effects if we don't do this. */
 226             unsigned int m = mask.GetCIDR();
 227             debugs(28, DBG_CRITICAL, "WARNING: IPv4 netmasks are particularly nasty when used to compare IPv6 to IPv4 ranges.");
 228             debugs(28, DBG_CRITICAL, "WARNING: For now we assume you meant to write /" << m);
 229             /* reset the mask completely, and crop to the CIDR boundary back properly. */
 230             mask.SetNoAddr();
 231             return mask.ApplyMask(m,AF_INET);
 232         }
 233 #endif /* USE_IPV6 */
 234         return true;
 235     }
 236
 237     return false;
 238 }
 239
 240 /* Handle either type of address, IPv6 will be discarded with a warning if disabled */
 241 #define SCAN_ACL1_6       "%[0123456789ABCDEFabcdef:]-%[0123456789ABCDEFabcdef:]/%[0123456789]"
 242 #define SCAN_ACL2_6       "%[0123456789ABCDEFabcdef:]-%[0123456789ABCDEFabcdef:]%c"
 243 #define SCAN_ACL3_6       "%[0123456789ABCDEFabcdef:]/%[0123456789]"
 244 #define SCAN_ACL4_6       "%[0123456789ABCDEFabcdef:]/%c"
 245 /* We DO need to know which is which though, for proper CIDR masking. */
 246 #define SCAN_ACL1_4       "%[0123456789.]-%[0123456789.]/%[0123456789.]"
 247 #define SCAN_ACL2_4       "%[0123456789.]-%[0123456789.]%c"
 248 #define SCAN_ACL3_4       "%[0123456789.]/%[0123456789.]"
 249 #define SCAN_ACL4_4       "%[0123456789.]/%c"
 250
 251 acl_ip_data *
 252 acl_ip_data::FactoryParse(const char *t)
 253 {
 254     LOCAL_ARRAY(char, addr1, 256);
 255     LOCAL_ARRAY(char, addr2, 256);
 256     LOCAL_ARRAY(char, mask, 256);
 257     acl_ip_data *r = NULL;
 258     acl_ip_data **Q = NULL;
 259     IpAddress temp;
 260     char c;
 261     unsigned int changed;
 262     acl_ip_data *q = new acl_ip_data;
 263     int iptype = AF_UNSPEC;
 264
 265     debugs(28, 5, "aclIpParseIpData: " << t);
 266
 267     /* Special ACL RHS "all" matches entire Internet */
 268     if (strcasecmp(t, "all") == 0) {
 269         q->addr1.SetAnyAddr();
 270         q->addr2.SetEmpty();
 271         q->mask.SetAnyAddr();
 272         return q;
 273     }
 274
 275 #if USE_IPV6
 276     /* Special ACL RHS "ipv6" matches IPv6-Unicast Internet */
 277     if (strcasecmp(t, "ipv6") == 0) {
 278         t = "2000::/3";
 279     }
 280 #endif
 281
 282 // IPv4
 283     if (sscanf(t, SCAN_ACL1_4, addr1, addr2, mask) == 3) {
 284         iptype=AF_INET;
 285     } else if (sscanf(t, SCAN_ACL2_4, addr1, addr2, &c) >= 2) {
 286         mask[0] = '\0';
 287         iptype=AF_INET;
 288     } else if (sscanf(t, SCAN_ACL3_4, addr1, mask) == 2) {
 289         addr2[0] = '\0';
 290         iptype=AF_INET;
 291     } else if (sscanf(t, SCAN_ACL4_4, addr1,&c) == 2) {
 292         addr2[0] = '\0';
 293         mask[0] = '\0';
 294         iptype=AF_INET;
 295
 296 // IPv6
 297     } else if (sscanf(t, SCAN_ACL1_6, addr1, addr2, mask) == 3) {
 298         iptype=AF_INET6;
 299     } else if (sscanf(t, SCAN_ACL2_6, addr1, addr2, &c) >= 2) {
 300         mask[0] = '\0';
 301         iptype=AF_INET6;
 302     } else if (sscanf(t, SCAN_ACL3_6, addr1, mask) == 2) {
 303         addr2[0] = '\0';
 304         iptype=AF_INET6;
 305     } else if (sscanf(t, SCAN_ACL4_6, addr1, mask) == 2) {
 306         addr2[0] = '\0';
 307         iptype=AF_INET6;
 308
 309 // Neither
 310     } else if (sscanf(t, "%[^/]/%s", addr1, mask) == 2) {
 311         addr2[0] = '\0';
 312     } else if (sscanf(t, "%s", addr1) == 1) {
 313         /*
 314          * Note, must use plain xgetaddrinfo() here because at startup
 315          * ipcache hasn't been initialized
 316          * TODO: offload this to one of the IpAddress lookups.
 317          */
 318
 319         debugs(28, 5, "aclIpParseIpData: Lookup Host/IP " << addr1);
 320         struct addrinfo *hp = NULL, *x = NULL;
 321         struct addrinfo hints;
 322         IpAddress *prev_addr = NULL;
 323
 324         memset(&hints, 0, sizeof(struct addrinfo));
 325
 326         if ( iptype != AF_UNSPEC ) {
 327             hints.ai_flags |= AI_NUMERICHOST;
 328         }
 329
 330 #if 0 && USE_IPV6 && !IPV6_SPECIAL_SPLITSTACK
 331         hints.ai_flags |= AI_V4MAPPED | AI_ALL;
 332 #endif
 333
 334         int errcode = xgetaddrinfo(addr1,NULL,&hints,&hp);
 335         if (hp == NULL) {
 336             debugs(28, 0, "aclIpParseIpData: Bad host/IP: '" << addr1 <<
 337                    "' in '" << t << "', flags=" << hints.ai_flags <<
 338                    " : (" << errcode << ") " << xgai_strerror(errcode) );
 339             self_destruct();
 340             return NULL;
 341         }
 342
 343         Q = &q;
 344
 345         for (x = hp; x != NULL;) {
 346             if ((r = *Q) == NULL)
 347                 r = *Q = new acl_ip_data;
 348
 349             /* getaddrinfo given a host has a nasty tendency to return duplicate addr's */
 350             /* BUT sorted fortunately, so we can drop most of them easily */
 351             r->addr1 = *x;
 352             x = x->ai_next;
 353             if ( prev_addr && r->addr1 == *prev_addr) {
 354                 debugs(28, 3, "aclIpParseIpData: Duplicate host/IP: '" << r->addr1 << "' dropped.");
 355                 delete r;
 356                 *Q = NULL;
 357                 continue;
 358             } else
 359                 prev_addr = &r->addr1;
 360
 361             debugs(28, 3, "aclIpParseIpData: Located host/IP: '" << r->addr1 << "'");
 362
 363             r->addr2.SetAnyAddr();
 364             r->mask.SetNoAddr();
 365
 366             Q = &r->next;
 367
 368             debugs(28, 3, "" << addr1 << " --> " << r->addr1 );
 369         }
 370
 371         if (*Q != NULL) {
 372             debugs(28, 0, "aclIpParseIpData: Bad host/IP: '" << t << "'");
 373             self_destruct();
 374             return NULL;
 375         }
 376
 377         xfreeaddrinfo(hp);
 378
 379         return q;
 380     }
 381
 382 #if !USE_IPV6
 383     /* ignore IPv6 addresses when built with IPv4-only */
 384     if ( iptype == AF_INET6 ) {
 385         debugs(28, 0, "aclIpParseIpData: IPv6 has not been enabled. build with '--enable-ipv6'");
 386         return NULL;
 387     }
 388 #endif
 389
 390     /* Decode addr1 */
 391     if (!*addr1 || !(q->addr1 = addr1)) {
 392         debugs(28, 0, "aclIpParseIpData: unknown first address in '" << t << "'");
 393         delete q;
 394         self_destruct();
 395         return NULL;
 396     }
 397
 398     /* Decode addr2 */
 399     if (!*addr2)
 400         q->addr2.SetAnyAddr();
 401     else if (!(q->addr2=addr2) ) {
 402         debugs(28, 0, "aclIpParseIpData: unknown second address in '" << t << "'");
 403         delete q;
 404         self_destruct();
 405         return NULL;
 406     }
 407
 408     /* Decode mask (NULL or empty means a exact host mask) */
 409     if (!DecodeMask(mask, q->mask, iptype)) {
 410         debugs(28, 0, "aclParseIpData: unknown netmask '" << mask << "' in '" << t << "'");
 411         delete q;
 412         self_destruct();
 413         return NULL;
 414     }
 415
 416     changed = 0;
 417     changed += q->addr1.ApplyMask(q->mask);
 418     changed += q->addr2.ApplyMask(q->mask);
 419
 420     if (changed)
 421         debugs(28, 0, "aclIpParseIpData: WARNING: Netmask masks away part of the specified IP in '" << t << "'");
 422
 423     /* 1.2.3.4/255.255.255.0  --> 1.2.3.0 */
 424     /* Same as IPv6 (not so trivial to depict) */
 425     return q;
 426 }
 427
 428 void
 429 ACLIP::parse()
 430 {
 431     char *t = NULL;
 432
 433     while ((t = strtokFile())) {
 434         acl_ip_data *q = acl_ip_data::FactoryParse(t);
 435
 436         while (q != NULL) {
 437             data = data->insert(q, acl_ip_data::NetworkCompare);
 438             q = q->next;
 439         }
 440     }
 441 }
 442
 443 ACLIP::~ACLIP()
 444 {
 445     if (data)
 446         data->destroy(IPSplay::DefaultFree);
 447 }
 448
 449 wordlist *
 450 ACLIP::dump() const
 451 {
 452     wordlist *w = NULL;
 453     data->walk (DumpIpListWalkee, &w);
 454     return w;
 455 }
 456
 457 bool
 458 ACLIP::empty () const
 459 {
 460     return data->empty();
 461 }
 462
 463 int
 464 ACLIP::match(IpAddress &clientip)
 465 {
 466     static acl_ip_data ClientAddress;
 467     /*
 468      * aclIpAddrNetworkCompare() takes two acl_ip_data pointers as
 469      * arguments, so we must create a fake one for the client's IP
 470      * address. Since we are scanning for a single IP mask and addr2
 471      * MUST be set to empty.
 472      */
 473     ClientAddress.addr1 = clientip;
 474     ClientAddress.addr2.SetEmpty();
 475     ClientAddress.mask.SetEmpty();
 476
 477     data = data->splay(&ClientAddress, aclIpAddrNetworkCompare);
 478     debugs(28, 3, "aclIpMatchIp: '" << clientip << "' " << (splayLastResult ? "NOT found" : "found"));
 479     return !splayLastResult;
 480 }
 481
 482 acl_ip_data::acl_ip_data () :addr1(), addr2(), mask(), next (NULL) {}
 483
 484 acl_ip_data::acl_ip_data (IpAddress const &anAddress1, IpAddress const &anAddress2, IpAddress const &aMask, acl_ip_data *aNext) : addr1(anAddress1), addr2(anAddress2), mask(aMask), next(aNext) {}